In the past, as an exhaust gas purification catalyst arranged in an exhaust passage of an internal combustion engine, there has been developed an electric heating catalyst (hereinafter referred to as an EHC) in which a catalyst is heated by means of a heat generation element which generates heat by electrical energization thereof.
In the EHC, an insulating member which serves to insulate electricity is arranged between the heat generation element which generates heat by electrical energization thereof, and a case in which the heat generation element is received. For example, in Patent Document 1, there is disclosed a technique in which in an EHC, a mat made of an insulating material is arranged between a carrier which is electrically energized to generate heat and a case in which the carrier is received. Due to the arrangement of such an insulating member, it is possible to suppress the heat generation element and the case from being short-circuited to each other.